1. Field of the Invention
The present invention generally relates to backflow preventers and sewer cleanouts, and more specifically to sewer line backflow preventers and cleanouts.
2. Background Information
Houses in modern residential areas are connected to municipal sewer lines by underground sewer pipes. If a house has a basement, the sewer lines are typically at a depth that the sewer line can go through the floor of the basement and under the basement walls. It is currently required that every such municipal sewer line connection to a house include a backflow preventer and an access for cleaning out the sewer line. The cleanout access is typically in the form of a Y, called a sanitary T, with an extension which reaches the ground level, and containing a plug which may be removed to allow clean out. The purpose of the cleanout is to allow periodic cleaning of the sewer lines from the house to the main sewer line.
Somewhere in the line, typically inside the house under the backflow preventer is a flap which allows fluid to flow in only one direction. When fluid flows from the opposite direction, the flap seals against a seat, preventing fluid from passing through the flap. The purpose of the backflow preventer is to keep sewage from backing up into the house in the event of a blockage of the municipal sewer line. Once the backflow preventer is installed, subsequent remodeling of the house can result in the backflow preventer being buried in a wall, covered by flooring, or the home owner may not know where it is. Locating the backflow preventer may be difficult, if not impossible, when it is necessary to clean the sewer line. In order to clean the sewer line between inside the house and the outside cleanout, it is necessary for a service person to enter the house with equipment, possibly soiling carpets and creating a mess where he is working, disrupting the household and requiring that some one be at home when the service is performed.
The backflow preventer is installed in a different location than the cleanout, and the cleaning tool must pass through it to clean from inside the house to the cleanout outside the house. The cleaning tool typically has rotating blades which scrape the sides of the sewer pipe. The rotating blades are extended into the sewer line by a cable. When the cleanout tool passes through the backflow preventer, it passes through in one direction without any problems. However, when the cleanout tool must be withdrawn from the line, it can snag on the backflow preventer, damaging or destroying the flap, or wearing a groove in one side of the backflow preventer which prohibits the backflow preventer from sealing against the flow of liquid. When the sewage line has a blockage, sewage will back up into every house in which the backflow preventer is not functioning properly, resulting in flooded basements and damaged or ruined walls, carpets, furniture and other household possessions. The municipality typically pays for these damages.
What is needed is a system that accomplishes the task of a backflow preventer, but allows a cleaning tool to pass through it without damaging it. Also needed is a method to allow access to sewer lines outside the house and permit cleaning of the all sewer lines both inside the house and outside.
Accordingly, it is the object of the present invention to provide a backflow preventer that can be cleaned out by a sewer line cleaning tool and not be damaged by passage of the cleanout tool. It is a further object to provide a sewer line cleanout access available at ground level outside of a house, and provide a bidirectional cleanout which allows the sewer line to be cleaned in two directions, toward the house and toward the municipal sewer line. This cleanout is to clean the entire line with no "dead" spots which are inaccessible to the sewer cleaning tool.
It is a further object to provide a backflow check valve that is replaceable and serviceable from ground level outside the house without digging, even though the backflow check valve may be located many feet under the ground.
Additional objects, advantages and novel features of the invention will be set forth in part in the description as follows, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.